Updated HysteresisCurve constructor so we can set minimum applied field (Hdc) independent of maximum applied field.
Add ComboBox for user to set maximum applied field.
Connect Maximum Applied Field combo box so user can control range of applied fields.
Also, some miscellaneous cleanup.
Merge pull request #1 from JeffMcKnight/ver_0_8_0

Version 0.8.0 - Add combo box so user can set maximum applied DC field, Hdc.